Currently, the valve of the prior art for shutting off gas flow is utilized in ordinary households, such as disclosed in U.S. Pat. No. 4,787,416 issued to the applicant, entitled "REGULATOR MEANS FOR AUTOMATICALLY SHUTTING PIPELINE PASSAGE OFF DURING PRESSURE REDUCING FAILURE". This valve permits natural gas therein to flow through the inlet of the valve to enter the transition room at the nozzle, and into the paths of the controlling valve by way of the exit of the transition room. Thus, the gas flows directly to the gas fixture. According to the paths of the gas flow, it is clear that the flow ways in the valve are not only narrow but not direct so as to reduce the flow badly. This reduces the pressure of the flow in some degree to diminish the fire on the gas fixture when the gas flows through the valve. The gas fixtures of the users, with connecting pipes to the low pressure ends of the natural gas piping systems, can scarcely get the gas at a peak use time such as in the evening when every family is cooking dinner. The above-mentioned disadvantages of the prior art make the valve unsuited to work under every condition and lead to design for an improvement.